Closure device for a centrifuge tube

ABSTRACT

The invention relates to a closure for a centrifuge tube, the centrifuge tube comprising an essentially cylindrical neck which forms an opening which can be closed by the closure. The invention is characterized by a lid with a cylindrical rim portion overlapping the neck, a number of cutouts arranged in a distributed manner on the periphery of the rim portion and a number of radially outwardly facing projections arranged in a distributed manner on the outer periphery of the neck. The projections can be brought into engagement with the associated cutouts of the lid when the lid is put onto the tube, locking in the manner of a bayonet closure taking place by a rotary movement of the lid. The invention relates likewise to an arrangement of projections on the inner rim region and cutouts on the neck of the centrifuge tube.

The invention relates to a closure for a centrifuge tube according to the preamble of the independent patent claims.

Various closure devices for centrifuge tubes are known from the prior art. What are known as Falcon tubes are as a rule provided with screw caps which, owing to the thread and for reasons of stability, are relatively clumsy. In practice, the closure lid must be screwed on and subsequently screwed off again via at least one thread turn, which in each case makes repeated gripping on opening and closing necessary. Moreover, the manufacture of these screw closures is rather costly and requires a relatively expensive tool.

In what are known as microliter receptacles, the closure has previously been in the form of a plastic stopper attached to the tube. However, a stopper is not optimal in terms of handling and involves the risk of unintentional opening.

The object of the invention is to produce an improved closure for a centrifuge tube, which closes the centrifuge tube reliably but can also be opened easily and rapidly.

According to the invention, this object is achieved by the features of the independent patent claims.

According to a first, preferred form of the invention, the closure comprises a lid with a cylindrical rim portion overlapping the neck, a number of cutouts arranged in a distributed manner on the periphery of the rim portion and a number of radially outwardly facing projections arranged in a distributed manner on the outer periphery of the neck. The projections can be brought into engagement with the associated cutouts of the lid when the lid is put onto the tube, locking in the manner of a bayonet closure taking place by a rotary movement of the lid.

The advantages of the invention are on the one hand that the centrifuge tube can be closed and opened again very easily and rapidly in comparison with tubes with conventional screw closures with a thread, and on the other hand that the manufacturing costs for both the tubes and the necessary tools are considerably lower than for tubes with threaded screw closures.

In comparison with the closures known for microliter receptacles, which are designed as a simple stopper, the closure according to the invention affords optimum closure reliability and tightness.

The cutouts are preferably designed as L-shaped slots in the lid, which are covered by webs at least in the region of the lower edge of the rim portion. These preferably outwardly curved webs serve to strengthen the closure cap and facilitate handling as no open slots or edges remain.

In another embodiment, however, the cutouts can also be designed in the form of a groove on the inner periphery of the rim portion. The cutouts are consequently not visible from the outside. In this connection, however, a greater wall thickness must be provided for the rim portion of the lid.

A second form of the invention provides a closure which comprises a lid with a cylindrical rim portion overlapping the neck, a number of radially inwardly facing projections arranged in a distributed manner on the inner periphery of the rim portion and a number of groove-shaped cutouts arranged in a distributed manner on the outer periphery of the neck. The projections can be brought into engagement with the associated cutouts of the neck when the lid is put onto the tube, locking in the manner of a bayonet closure taking place by a rotary movement of the lid.

In the second form of the invention, the arrangement of the projections and cutouts is simply reversed in comparison with the first form.

In a machining center, the cutouts can be made much more easily on the outer edge (neck) of a tube or cup, in particular one made of metal, than on the inner edge of the lid, which is made in particular of plastic, in particular by means of an injection-molding die.

To realize the bayonet principle, the cutouts are of roughly L-shaped design in both forms described.

In order to centrifuge the contents of the closed centrifuge tubes, the tubes have to be fastened to the rotor of the centrifuge. To this end, rigidly or pivotably arranged holding devices, which receive the individual centrifuge tubes, are provided on the rotor of the centrifuge in a known way.

Therefore, in an advantageous development of the invention, the lid itself forms the holding device for the centrifuge tube by virtue of a hook-shaped extension being provided on the upper side of the lid. This hook-shaped extension can be hung in a corresponding opening provided on the rotor of a centrifuge. A special holding device for the centrifuge tubes on the rotor is consequently no longer necessary, as a result of which the manufacturing costs and the overall mass of the rotor to be accelerated are reduced.

Conversely, it is of course possible that the lid forms an essentially horizontally aligned opening on the upper side, which can be hung in a hook-shaped extension provided on the rotor of a centrifuge.

The closure according to the invention can find application in particular with microliter receptacles and Falcon receptacles.

Preferred illustrative embodiments of the invention are described in greater detail below with reference to the drawings. Other features, advantages and possible applications of the invention emerge from the drawings and their description.

FIG. 1 shows a closure according to the invention for a centrifuge tube using the example of a microliter receptacle;

FIG. 2 shows a closure according to the invention with a hook-shaped extension;

FIG. 3 is an enlarged illustration of FIG. 2;

FIG. 4 shows a centrifuge rotor with six microliter centrifuge tubes hung in the rotor by means of their closure lid;

FIG. 5 shows a centrifuge tube of the Falcon type with the lid open;

FIG. 6 shows a centrifuge tube of the Falcon type with the lid closed;

FIG. 7 shows a perspective exploded illustration of a centrifuge cup according to the invention with a closure lid in an alternative embodiment;

FIG. 8 shows an enlarged illustration of the closure lid from FIG. 7, and

FIG. 9 shows an enlarged illustration of the centrifuge cup from FIG. 7.

A microliter centrifuge tube 1 is illustrated in FIG. 1. The tube 1 is closed at one end and has in the region of the neck 2 an opening which can be closed by a lid 4. This closure is designed as what is known as a bayonet closure. For this purpose, a number of projections 3, which engage in associated cutouts 6 provided in the rim region 5 of the lid 4, are provided in a distributed manner over the periphery on the neck 2 of the tube 1. The cutouts 6 are of roughly L-shaped design and are open toward the lower edge of the rim portion 5, so that, when the lid 4 is put onto the neck 2 of the tube 1, the projections 3 engage in the cutouts 6 and, by rotation, move along in the slots and lock the lid firmly on the tube 1. For closing, only a slight rotary movement is necessary, for example only an eighth of a turn of the lid 4. A slight rotation is likewise sufficient for removing the lid 4. The lower region of the cutout 6 is preferably covered by a web 7, which on the one hand increases the stability of the lid and on the other hand improves handling.

In a preferred form of the invention according to FIGS. 2 and 3, the lid 4 is provided with an axially upwardly directed hook-shaped extension 8. After the tube 1 has been closed by the lid 4, the whole arrangement can then be hung in a corresponding disk 10, provided with openings 11, of a centrifuge rotor 9 by means of the hook-shaped extension 8, as is illustrated in FIG. 4. Separate holding devices for receiving the tubes in the centrifuge rotor 9 are consequently unnecessary. On the one hand, this type of fastening of the centrifuge tubes 1 can be achieved very cost-effectively, and, on the other hand, the mass of the rotor to be moved is reduced as a result. This fastening of the tubes allows the tubes to swing outwardly horizontally during operation of the centrifuge.

FIGS. 5 and 6 show centrifuge tubes 13 of the Falcon type, which have a greater volume in relation to the microliter receptacles. FIG. 5 shows the receptacle 13 with the lid 4 open and FIG. 6 with the lid 4 closed.

The bayonet closure according to the invention affords considerable advantages in the case of Falcon receptacles as well, which are usually equipped with a threaded screw closure.

FIG. 7 shows a perspective exploded illustration of a centrifuge cup 14 according to the invention with a closure lid 15 in an alternative embodiment, the cup 14 and the lid 15 being sealed in a liquidtight manner in relation to one another via an O-ring seal 16. The seal 16 lies on an inner annular projection 17 of the lid 15 and, when the lid 15 has been put onto the cup 14, bears on the end annular edge 18 of the cup 14.

The closure lid 15 has eight projections 19 which are arranged in an evenly distributed manner on the inner periphery of the axially open rim portion 20 of the lid 15. The projections 19 have the shape of a half-cylinder which is cut off in the direction of its longitudinal axis, the cylindrical lateral side of the projections 19 facing axially into the interior of the lid 15, while the flat cut surface faces axially out of the interior of the lid 15 in the direction of the cup 14 in FIG. 7. Lying axially opposite the projections 19 is a dome 21 which terminates the lid 15.

Numerous raised portions 22, which are intended to prevent the fingers of the user slipping off during opening and closing of the lid 15, are present on the outer periphery of the lid 15.

The cup 14 has on the outer periphery of its neck 23 eight cutouts 24 which interact with the projections 19 of the lid 15 for opening or closing the cup 14.

The number of projections 19 of the lid 15 and the number of cutouts 24 of the cup 14 are preferably the same, but this is not necessary for the solution. In other embodiments, more cutouts 24 than projections 19 are present.

The cutouts 24 of the cup 14 are moreover of L-shaped design and are open toward the axially open end of the cup 14, so that the projections 19 of the lid 15 can be introduced axially there. The lid 15 is then, after the projections 19 have reached the lower L-leg of the cutouts 24, rotated by approximately 5°-10° in relation to the cup 14 and the projections 19 then catch in an axial undercut 24 a. The projections 19 of the lid 15 and the cutouts 24 of the cup 14 thus correspond to a conventional bayonet closure.

Toward the bottom, the cup 14 is terminated by a bottom 25, the outer casing of the cup 14 having two diameter steps 26, 27, the larger diameter 26 of which is located at the open neck 23 and the smaller diameter 27 of which is located in the region of the bottom 25.

A groove 28, which is open radially outwardly and axially in the direction of the bottom 25 and serves for mounting in the centrifuge (not illustrated), also extends axially on the outer casing of the cup 14.

Drawing Legend

-   1 microliter centrifuge tube -   2 neck -   3 projection -   4 lid -   5 rim portion -   6 cutout -   7 web -   8 hook-shaped extension -   9 centrifuge rotor -   10 disk -   11 opening -   12 arrow direction -   13 Falcon centrifuge tube -   14 cup -   15 closure lid -   16 ring seal -   17 annular projection of 15 -   18 annular edge of 14 -   19 projections of 15 -   20 rim portion of 15 -   21 dome of 15 -   22 raised portions of 15 -   23 neck of 14 -   24 cutouts of 14; 24 a undercut of 24 -   25 bottom of 14 -   26 large diameter step of 14 -   27 small diameter step of 14 -   28 groove in 14 

1. A closure for a centrifuge tube, the centrifuge tube (1; 13) comprising an essentially cylindrical neck (2) which forms an opening which can be closed by the closure, which comprises: a lid (4) with a cylindrical rim portion (5) overlapping the neck, a number of cutouts (6) arranged in a distributed manner on the periphery of the rim portion (5), a number of radially outwardly facing projections (3) arranged in a distributed manner on the outer periphery of the neck (2), where the projections (3) can be brought into engagement with the associated cutouts (6) of the lid when the lid (4) is put onto the tube (1; 13), locking in the manner of a bayonet closure taking place by a rotary movement of the lid.
 2. The closure as claimed in claim 1, wherein the cutouts (6) are covered by webs (7) at least in the region of the lower edge of the rim portion (5).
 3. The closure as claimed in claim 1, wherein the cutouts (6) are designed in the form of a groove on the inner periphery of the rim portion (5).
 4. A closure for a centrifuge tube, the centrifuge tube being designed in particular as a cup (14) and comprising an essentially cylindrical neck (23) which forms an opening which can be closed by the closure, which comprises: a lid (15) with a cylindrical rim portion (20) overlapping the neck (23), a number of radially inwardly facing projections (19) arranged in a distributed manner on the inner periphery of the rim portion (20), a number of groove-shaped cutouts (24) arranged in a distributed manner on the outer periphery of the neck (23), where the projections (19) can be brought into engagement with the associated cutouts (24) of the neck (23) when the lid (15) is put onto the cup (14), locking in the manner of a bayonet closure taking place by a rotary movement of the lid (15).
 5. The closure as claimed in claim 1, wherein the cutouts (6) are of roughly L-shaped design.
 6. The closure as claimed in claim 1, wherein the lid (4) has a hook-shaped extension (8) on the upper side, which can be hung in a corresponding opening (11) provided on the rotor (9) of a centrifuge.
 7. The closure as claimed in claim 1, wherein the lid (4) forms an essentially horizontally aligned opening on the upper side, which can be hung in a hook-shaped extension provided on the rotor (9) of a centrifuge.
 8. The closure as claimed in claim 1, which finds application in particular with microliter receptacles and Falcon receptacles and also cup-like receptacles (14).
 9. The closure as claimed in claim 4, wherein the cutouts (24) are of roughly L-shaped design.
 10. The closure as claimed in claim 4, wherein the lid (15) has a hook-shaped extension on the upper side, which can be hung in a corresponding opening provided on the rotor of a centrifuge.
 11. The closure as claimed in claim 4, wherein the lid (15) forms an essentially horizontally aligned opening on the upper side, which can be hung in a hook-shaped extension provided on the rotor of a centrifuge.
 12. The closure as claimed in claim 4, which finds application in particular with microliter receptacles and Falcon receptacles and also cup-like receptacles. 